GROUND-source Heat Pump

GROUND as a renewable energy source

Renewable energy is energy which comes from natural resources that are naturally regenerative or are practically inexhaustible such as sunlight, wind, air and geothermal heat.

Let’s focus on the last one. Geothermal energy is the heat that is stored into the ground. This huge amount of energy can be recovered installing a geothermal (ground-source) systems.
They are basically closed loop installations able to recover energy from the soil using either vertical or horizontal water heat exchangers directly buried into the ground. Cold water-glycol mixture flows inside the loop at a lower temperature than the soil and therefore recovers renewable energy.
During winter time the energy flows from the ground to the heat pump and vice versa during summer time.

Due to the enormous mass of the soil, the temperature of the ground is nearly constant year round and it is independent from the weather conditions (see picture on the left).
One of the major advantages of a geothermal installation is that the temperature of the ground does not change year round. The year round temperature fluctuation at a depth of 30ft. is only +/- 2°F (almost negligible) and below 50ft. is negligible at all.

This means that the performance of the system is not affected by the weather conditions and therefore the seasonal performance factor of the unit is normally higher if compared to an air source installation.
This is the reason why, unlike the Air Source Heat Pumps, the Ground Source Heat Pumps (GSHP) can achieve high performances even if installed in very cold climate zones.